2209640 has 32 divisors (see below), whose sum is σ = 5109480. Its totient is φ = 859392.

The previous prime is 2209639. The next prime is 2209661. The reversal of 2209640 is 469022.

2209640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 2208196 + 1444 = 1486^2 + 38^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 734 + ... + 2226.

2^2209640 is an apocalyptic number.

2209640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2209640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2554740).

2209640 is an abundant number, since it is smaller than the sum of its proper divisors (2899840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2209640 is a wasteful number, since it uses less digits than its factorization.

2209640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1541 (or 1537 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 2209640 is about 1486.4857886976. The cubic root of 2209640 is about 130.2488330693.

The spelling of 2209640 in words is "two million, two hundred nine thousand, six hundred forty".